Work loading device for grinding machines



J 9- A. J. JONES ETAL 2,472,707

WORK LOADING DEVICE FOR GRINDING MACHINES Filed Sept. 20, 1945 3Sheets-Sheet 1 IN VENTOR #1. W a. JONES 0.6. WALKER WILLIAMS ATTORNEYJune 7, 1949. JONES AL 2,472,707

I WORK LOADING DEVICE FOR GRINDING MACHINES Filed Sept. 20, 1945 5Sheets-Sheet 2 k INYENTOR El Q \1- 4: VIN .1. Mavis Ll: Claw/KER)V/LL/4M3 47 g yQNL/ ATTORNEY June 7, 1949. JONES AL 2,472,707

WORK LOADING DEVICE FOR GRINDING MACHINES Filed Sept. 20, 1945 3Sheets-Sheet 3 INVEN TOR 41w 4. Joya:- c. a. ma #5,? Ma mus Md. 7 )4)?ATTORNEY Patentc'diilune 7, 1949 2,472,701 WORK LOADING DEVICE FORGRINDING MAC HINES- Alvin'J. Jones and Charles Clement -Walker-Williams,Waynesboro, Pa., asslgnors to Landis Too Company, Waynesboro, Pa.

Application September 2t), 1945, Serial No. 617,540

This invention relates to machine tools particularly to grindingmachines of the centerless I type and means for supplying work piecesthereto for a grinding operation.

This invention is particularly suited to supplying work pieces to acenterless grinder for a through feed operation although it may also beused to supply work pieces for a plunge cut operation.

- For the purpose of illustration the invention is disclosed as a workloading device in combination with a centerless grindin machine set upto produce headless screws from solid stock by the through feed methodof centerless grinding. A similar machine is shown in detail inco-pending application Serial No. 543,780, filed July '7, 1944.

In supplying blank work pieces to a centerless grinder for the purposeof forming screw threads thereon it is desirable from the standpoint ofproduction that they enter the grinding throat with successive pieces incontact with one another. At the same time it: is just as desirable thatthe pieces are not forced through the grinding throat.

The rate of feed through the machine is determined by the combination ofthe angular speed and angle of tilt of the control wheel. This ratemustbe such that grinding ridges which form the thread neither act toretard the feed, which would be the case if the work was being forcedunduly by axial pressure, nor to advance the feed, which would occur ifthe control wheel was not set at the proper angle.

It is therefore an object of my invention to provide means for supplyingwork pieces to a centerless grinder with a minimum application of force.

A further object is to substantially eliminate gravity as ordinarilyused for motive power in such cases.

A further object is to provide means whereby the work blanks will becaused to move along a horizontal path or even up an incline inapproaching the grindin throat. I

A further object isto provide a hopper from which the work will flowwithout interruption.

A further object is to provide means for returning the finished work tothe operator.

A further object is to provide a work feeding device of the vibratortype consisting of a hopper and a conveyor, said hopper and saidconveyor 3 Claims. (01. 51-103) being vibrated as a unit by a singlevibrating' means.

In the drawings Figure 1 is a perspective view of a centerless grinderwith a work feeding device mounted thereon.

Figure 2 is a sectional elevation showing two conveyor mechanisms on acenterless grinder, one

' for feeding the work to the grinding throat, the

other for returning the ground piece to the operator.

Figure 3 is a partial end elevation of hopper shown in Figure 2'.

Figure 4 is a series of drawings showing the method of operation of thefeeding device.

Figure 4A shows the loader with the solenoid in deener'gized positionwith the work piece at an elevation indicated by the centerline.

Figure 4B shows the loader position with the solenoid energized.

Figure 4C shows the loader with the solenoid still energized and thework piece in an advanced position on the work supporting member but ata lower elevation than in Figures 4A and 4B.

Figure 4D shows the loader with the solenoid de-energized and the loadermoved upward and forward by the spring supports to an advanced positionrelative to the grinding wheel.

The centerless grindin machine which forms a part of our invention issubstantially identical with that disclosed in application Serial No.543,780, filed July 7, 1944. It consists briefly of a bed III, agrinding wheel support ll slidably mounted thereon for movementtransversely of the wheel axis toward and from operative position. Agrinding wheel I2 having a grinding surface formed to correspond to theshape of the work to be ground, in this case screw threads, is rotatablymounted on said base ll.

Also slidably mounted on said bed is a control wheelsupport H in whichis rotatably mounted a control wheel Hi. Said control wheel support ismounted for adjustment toward and from the grinding wheel. A work restI! is mounted on the bed between the operative surfaces of said wheels.The space bounded by the said wheel surfaces and the work rest iscommonly known as the grinding throat.

The means for introducin work pieces into' the grinding throat consistsof a hopper 20 having a V-shaped bottom. A baflle is formed by aninverted V-shaped plate 2| spaced from the walls of the hopper by anamount to permit a controlled flow of work pieces therebetween toth'ebottom of the hopper. Said baflle is mounted on a pair of pins 22. I

An opening 25 at one end of the hopper in line with the bottom of theV-shaped portion is made adjustable by means of two strips 26 and 21movable along the sides of the V and toward and from the bottom thereof.Thus the opening through which the work pieces must pass is adjustablefor a variety of size so that for any size the work pieces must leavethe hopper one at a time. The V-shaped bottom of the hopper is inefl'ect extended in the form of a trough 30 having an opening Si in theside and at the bottom thereof so that only a single piece may pass thispoint at one time. If there are two or more pieces moving together in apile, all but one will drop through the opening to a suitablereceptacle. From said trough, a tube 32 extends to a point just short ofthe edge of the grinding wheel.

The hopper. trough and tube form a single unit which is mounted by meansof pins on a block 35 which in turn is attached to a vibrating device.Said vibrating device consists of a base member 40 resiliently supportedon springs 4|. An electro-magnet 42 is mounted on said base with itsaxis at an angle to the horizontal. A pair of fiat springs 43 and 44 aremounted on said base approximately perpendicular to the axis of saidmagnet. Said springs are joined by a connecting member 45. An externalarmature 41 is attached to the spring 44 so that when magnet 42 israpidly energized and de-energized the springs and connecting member aresubject to a vibrating movement which occurs in a directionsubstantially parallel with the axis of said magnet.

The magnet 42 is powered by periodic direct current supplied through arectifier 41 from a suitable source. The frequency of vibration isdetermined by the frequency of the source of alternating current used.The amplitude of vibration which determines the rate of feed of the workpieces is controlled by a rheostat 48.

work and wheel does not change.

While an electro-magnetic vibrator is shown,

fluid or mechanical power could be used with satisfactory results.

The block 35 to which the conveyor unit is attached is mounted on theconnecting member. Thus the conveyor unit is also vibrated in adirection parallel to the axis of the magnet. Vibration of the conveyorin this direction has the effect of causing workpieces 33 to move intothe grinding throat when," the trough and tube are horizontal and evenif they are slightly inclined upwardly.

In order to return finish ground work pieces to the operator or to shiftthem to any other position a second conveyor is used. An inclinedtubular member receives the finished piece and discharges it at a lowerlevel into a second tube 5| having an upwardly turned end portion 52 orother suitable means for receiving a work piece from the first tube 50.Tube 5| extends back under the work rest and through the front of themachine. Tube 5i is inclined slightly upwardly toward the front of themachine so that coolant does not return with the work. Said coolant isdrained off through openings 53 in the bottom of tube 5!. The front endof tube 5| is supported in a sleeve 54. One end of said sleeve isattached to the bed of the machine by a resilient connection 55. Theother end is secured in a bracket 56. Said bracket is attached to theconnecting member 45' of a second vibrator device located beneath thefirst mentioned vibrator and in a reverse position relative thereto. Thefirst or upper vibratory conveyor causes work pieces to move from leftto right in Figure 2. The second or lower conveyor causes work pieces tomove from iflhttoleit.

The manner in which the vibrator moves the work pieces is disclosed inFigures 4a and 4b.

In Figure 4a the parts are shown in normal position with the magnet 42deenergized. The centerline of the work is indicated by the letter C.

In Figure 4b, magnet 42 has been energized and the work supportingportion of the vibrator has moved to the solid line position against theresistance of fiat springs 43 and 44. This movement takes place sorapidly that in efiect the work pieces are left hanging in space.However, due to the force of gravity, they do drop to the worksupporting member as shown in Figure 40, while the magnet is energized.The work pieces drop vertically to the centerline C, and since themovement of the supporting member is downward and to the rear, the workpieces land in a slightly ad vanced position on said support as shown inFigure 40.

In Figure 4d the magnet is deenergized and the work supporting membertogether with the parts are returned to normal position by means of fiatsprings 43 and 44. Since the work pieces have assumed an advanceposition on the support as described above, then when the support isreturned to normal position the work pieces will likewise be moved to anadvanced position relative to the'grinding throat. Said throat isrepresented in Figures 4a and 4d by the control wheel Hi. It will benoted in the drawing that in Figures 4a, 4b and 4c the relative positionof the In Figure 4d however the work piece which was only partly withinthe throat in the first three views is now entirely therein,

We claim:

1. In a centerless grinding machine opposed grinding and control wheels,means for supporting work to be ground between said wheels, saidelements being arranged to provide a grinding throat, said control wheedbeing tilted to feed the work axially past the grinding wheel, means tofeed unground work pieces to said work supporting means at substantiallythe same rate including a conveyor member and a vibrating device foractuating same, a hopper for supplying a succession of work pieces tosaid conveyor, said hopper consisting of a container, a baffle plate insaid container, the edge of said plate being spaced from the sides ofsaid container to permit a controlled flow of said work pieces to thebottom of said container said conveyor extending from said hopper tosaid grinding throat.

2. In a. centerless grinding machine, a grinding wheel, a work rest anda control wheel forming a grinding throat, said control wheel beingtilted relative to the grinding wheel so as to feed work pieces throughsaid grinding throat at a predetermined rate, means to supply workpieces to said grinding throat at substantially the same rate includinga vibratory conveyor substantially level with said grinding throat andvibrating means for actuating said conveyor, a hopper having a baffleplate therein for supplying work pieces to said conveyor at a controlledrate, said hopper and said conveyor being vibrated as a unit.

3. A centerless grinding machine including a control wheel, a work restand a grinding wheel, said control wheel being tilted relative to saidgrinding wheel, whereby to feed the work piece axially at the properrate, means for supplying work pieces to the machine along a horizontalpath at a rate no faster than said axial feed movement including avibratory conveyor supported in operative relation to said work support,

a vibrator for said conveyor, a hopper for sunplying work blanks to saidconveyor at a controlled rate, said conveyor having a lateral openingtherein, at which point said conveyor can support only one work piece ata time, all blanks in excess of one passing through said opening,whereby a succession of single blanks moves toward grinding position.

ALVIN J. JONES. C. C. WALKER WILLIAMS.

REFERENCES CITED The following referenlces are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,837,821 Holmes Dec. 22, 19311,848,676 Swanson Mar. 8, 1932 1,850,373 Booth 1 Mar. 22, 1932 2,116,031Lindner May 3, 1938 2,187,717 Weyandt Jan. 23, 1940 2,260,843 StrongOct. 28, 1941 2,305,943 Weyandt Dec. 22, 1942 2,377,982 Theier et a1June 12, 1945 5 published in April 1915 issue of Screw MachineEngineering.

